FISHERIES AND MARINE SERVICE
Translation Series No. 3889 RE R.
Decapoda, Pantopoda LIBRARY FISHERIES AND OCEANS BIBLIOTHÈQUE PELHLS ET OCÉANS
by V. A. Yashnov and E. S. Bronshtein
Original title: Desyatinogiye raki, Piknogony
From: In Keys to the fauna and flora of northern seas of the USSR, 1948 p. 328-351
Translated by the Translation Bureau (NDe) Multilingual Services Division Department of the Secretary of State of Canada
Department of the Environment Fisheries and Marine Service Freshwater Institute Winnipeg, Man. 1976
43 pages typescript .t Follinw3n>9
DEPARTMENT OF THE SECRETARY OF STATE SECRÉTARIAT D'ÉTAT TRANSLATION BUREAU BUREAU DES TRADUCTIONS É+ 4.i 11> MULTILINGUAL SERVICES DIVISION DES SERVICES CANADA DIVISION MULTILINGUES
TRANSLATED FROM — TRADUCTION DE INTO — EN Russian English
AUTHOR — AUTEUR V.A. Yashnov, E.S. Bronshtein
TITLE IN ENGLISH — TITRE ANGLAIS Decapoda, Pantopoda
TITLE IN FOREIGN LANGUAGE (TRANSLITERATE FOREIGN CHARACTERS) TITRE EN LANGUE ÉTRANGÉRE (TRANSCRIRE EN CARACTERES ROMAINS) Desyatinogiye raki, Piknogony
REFERENCE IN FOREIGN LANGUAGE (NAME OF BOOK OR PUBLICATION) IN FULL. TRANSLITERATE,FOREIGN CHARACTERS. RÉFÉRENCE EN LANGUE ÉTRANGÉRE (NOM DU LIVRE OU PUBLICATION), 'di COMPLET, TRANSCRIRE EN CARACT'ERES ROMAINS. Opredelitel' fauny i flory severnykh morei SSSR
REFERENCE IN ENGLISH — RÉFÉRENCE EN ANGLAIS Keys to the fauna and flora of the northern seas of the USSR
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_ CLIENTS NO. DEPARTMENT DIVISION/BRANCH CITY N° DU CLIENT MINISTÉRE DIVISION/DIRECTION VILLE Environment Fisheries & Marine Winnipeg, Man.
BUREAU NO. LANGUAGE -_ TRANSLATOR (INITIALS) N° DU BUREAU LANGUE TRADUCTEUR (INITIALES) 1101537 Russian N. De. DEC - 8 1975
Opredeliter fauny i flory severnykh morei SSSR, 1948, pp. 328-351 Lef,cererm Trci.nsurioN Order DECAPODA TRA17= By = =0 EE V.A. Yashnov informanon sou:erne:1f (328)*
The Decapoda consist primarily of marine organisms which lead a
benthic, much lesscommonly pelagic, mode of life. A large number of species
inhabit tropical and temperate seas; a comparatively small number of species
is encountered in the northern seas of the USSR.
The body of Decapoda consists of a cephalothorax and abdomen (fig.
34). All the segments of the cephalothorax are covered with a carapace
which is fused with them at the top; in rarer cases one or two of the last
thoracomeres remain separate. In many species, primarily natatory ones, the
anterior part of the carapace turns into a rostrum, the armature of which
is of great -taxonomic significance; in bottom-dwelling species the rostrum
is often reduced or absent altogether. The exterior of the carapace is :
usually covered with spines, teeth or hairs, particularly in species with (329)
highly calcareous integuments. The abdomen in the Macrura group is elongate,
with well-developed and mobile segments bearing epimera along the sides;
The numbers in the right-hand margin are the pages of the Russian text - translator.
SEC 5-25T (6/76) in the Brachyura group it is contracted and bent under the cephalothorax;
the abdomen of hermit crabs (Paguridae) resembles a soft, unsegmented sac,
mostly spiral-shaped. The anterior end of the cephalothorax carries paired,
stalked eyes, antennules and antennae. The antennules consist of a 3-
segmented stem and two, less commonly three, flagella.
-°
Fig. 34 Decapoda (Sclerocrangon ferox). side view of female, Ab - abdomen, Cth - cephalothorax, al - antennule, a2 - antenna, enp - endopodite, exp - expodite, fl - flagellum, ml - maxil- lula, m2 - maxilla, md - mandible, mpl - first maxilliped, mp2 - second
maxilliped, mp3 - third maxilliped, p thoracopods, p4 - fourth thoracopod,
pl - pleopods, p14 - fourth pleopod, t telson, up - uropods.
3 The antennaeconsist of a stem in 2-5 segments and a multiarticulate flagell- um; in many species a process (exopodite) called the scaphocerite or squama, which resembles a spine or broad plate with a thickened outer edge bearing a tooth on the distal end, extends from the second segment of the stem.
The mouth parts are formed by the mandibles, maxillulae, maxillae and three pairs of maxillipeds. The last five pairs of appendages of the cephalothorax are perefods. In a typical case, e.g., in members of the Macrura group
(fig. 34), they consist of seven segments; the most clearly demarcated articulation is observed between the meropodite and carpopodite. In the majority of Anomura and Brachyura the basipodite and meropodite of the per^pods are fused together, due to which the legs consist of six segments.
The per'eôpods of mature individuals are almost always uniramous,exopodites (330) being present only in a very small number of species. Gill appendages extend from the basal segments of the perepods; gill appendages may also be present on the lateral surface of the thoracic segments. The first pair of pereopods are almost always supplied with chelae (chelipeds); in many species chelae are present on other legs as well. In structure we dis- tinguish between the true chela and the false chela. The true chela
(chela) is formed by two parallel fingers of equal length, of which the movable one is the last segment of the leg (dactylopodite) and the immovable one is formed by a long process (pollex) of the second last segment (pro- podite). The proximal part of the propodite from its base to the line passing through the articulation of the propodite with the dactylopodite
is called the palma. In the false chela (sub-chela) the immovable finger
is represented by a short process stemming from one of the corners of the
anterior margin of the expanded propodite; the movable finger (dactylo-
podite), which is articulated to the opposite corner of the propodite,
pushes against its anterior edge when bent, touching the immovable finger 4 only with its tip. The abdominal appendages of Macrura consist of five pairs of biramous pleopods which are used for swimming and one pair of uropods. The pleopods of Anomura are reduced and are present on only some of the abdominal segments; uropods are almost always present. In Brachyura uropods are lacking altogether.
All Decapoda are dioecious, hermaphroditism being observed in rare cases only. The eggs that the females carry on their pleopods for a more or less lengthy period of time develop into larvae which lead a free mode of life. During the development of decapods, various larval stages are formed, among which we distinguish the stage of nauplius, metanauplius, " protozoea, zoea, the mysis stadium and decapodite stadium. However, the development process does not always include all these stages, some are bypassed. Below (p. 24) we present keys to the larval stages of Decapoda and descriptions of the larvae of certain species.
The order Decapoda falls into four suborders which are characterized by the following features:
SuborderMacrura natantia(shrimps). Body more or
less highly compressed laterally; abdomen longer than cephalothorax, with well-developed epimera. Rostrum almost always present. Antennae with large
scaphocerites and long flagella. Pereopods long and slender. Pleopods biramous, adapted for swimming. Body integuments slightly calcareous. Sub-
order includes the best swimmers among decapods.
SuborderMacrura reptantia(lobsters and crayfish).
Similar to members of preceding suborder in form of body. Distinguished by
highly calcareous body integuments, as well as by strongly developed cheli-
peds (those encountered in northern seas of the USSR). Lead benthic mode
of life.
SuborderAnomura. Form of body diverse. Abdomen elongate, or 5
flattened and bent under cephalothorax, or sa6ular and thin-walled.
Scaphocerites usually present. First pair of pereopods bear chelae; fifth pair of pereopods always differs from third pair in size. Uropods usually, though not always, present. Crabs belonging to suborder Anomura (Lithodidae) distinguished from true crabs by the fact that the last pair of pereopods are highly reduced and bent under the cephalothorax, which gives these crabs (sometimes called craboids*) the appearance of having four pairs of legs; this feature makes it easy to distinguish "octopod" craboids from true decapod crabs.
SuborderBrachyura(crabs). Cephalothorax highly expanded and flattened. Abdomen small, flattened, lacking uropods, bent under cephalo- thorax and, therefore, invisible from above. Antennules and antennae poorly developed. Body integuments highly calcareous. Typical bottom dwellers, only a few species able to swim.
The Decapoda of the northern seas of the USSR have been studied more or less in detail. The Barents Sea is the most abundant in decapods.
Decapoda are an important food for various types of organisms, includ- ing commercial species of fish. The diet of cods consists primarily of shrimps
(Yandalus borealis and Sabinea septemcarinata); bottom fish feed on crabs and hermit crabs.
Key to genera of Decapoda encountered (331)
in northern seas of the USSR
1 (2) Abdomen soft, unsegmented; organisms live in mollusk shells
Pagurus
2 (1) Abdomen segmented 3
This word, coined by L. G. Vinogradov, has not achieved popular acceptance, so the species below are more likely to be called "crab" (Russian-English Dictionary for Students of Fisheries and Aquatic Biology by W.E. Ricker). 6
3 (38) Abdomen elongate, with well-developed uropods ...... 4
4 (5) Last four pairs of pereopods with exopodites...... Hymenodora
5 (4) Pereopods lacking exopodites ...... 6
6 (7) Third pair of per6pods with chelae; organisms similar in
appearance to freshwater crayfish ...... Nephrops
7 (6) Third pair of pereopods lacking chelae ...... 8
8 (35) Abdomen considerably longer than cephalothorax; epimera of
second abdominal segment expanded and partially cover epimera
of first and third abdominal segments ...... 9
9 (12) First pair of pereopods cuspidate ...... 10
10 (11) Rostrum not shorter than carapace ...... Pandalus
11 (10) Rostrum not longer than half of carapace ...... Pandalina
12 (9) First pair of pereopods with well-developed chelae...... 13
13 (26) First pair of pereopods terminate in true chelae with two
parallel fingers ...... 14
14 (15) Carpopodite of second pair of pereopods divided into two
secondary segments ...... Caridion
15 (14) Carpopodite of second pair of pereopods divided into large
number of secondary segments ...... 16
16 (17) Rostrum broad and short, with three cuspidate spines (one
median and two lateral) on end ...... Bythocaris
17 (16) Rostrum narrow, without lateral spines ...... 18
18 (19) Terminal segments of last three pairs of pereopods smooth
along lower edge ...... Spirontocarella
19 (18) Terminal segments of last three pairs of pereopods bear
spines along lower edge ...... 20
20 (23) Anterior part of carapace bears one or several supraorbital
spines on each side ...... 21 7
21 (22) Carapace bears two supraorbital spines on each side (some-
times the one on the edge of the orbit is small and barely
visible) Spirontocaris
22 (21) Carapace bears one supraorbital spine on each side Hetairus
23 (20) Anterior of carapace lacking supraorbital spines (spines present
only at base of scaphocerites and on anterior lower corners of
carapace) 24
24 (25) Rostrum long, not less than length of scaphocerites....Eualus
25 (24) Rostrum short, not longer than one-third of scaphocerites
Hep tacarpus
26 (13) First pair of pereopods terminate in subchelae (movable finger
bends toward anterior edge of expanded propodite) 27
27 (28) Eyes almost concealed in tubular sheath formed by expansions
of frontal margin of carapace Nectocrangon
28 (27) Eyes free 29
29 (30) Second pair of pereopods lacking chelae Sabinea
30 (29) Second pair of pereopods terminate in small chelae 31
31 (32) Second pair of pereopods considerably shorter than first
pair Pontophilus
32 (31) Second pair of pereopods do not differ in length from first
pair 33
33 (34) Dorsal surface of carapace lacking ornament, smooth.... Crangon
34 (33) Dorsal surface of carapace with more or less sharply
defined ornament Sclerocrangon
35 (3) Abdomen approximately equal in length to cephalothorax;
epimera of second abdominal segment not expanded 36
36 (37) Rostrum triangular, with three pairs of lateral (332)
spines Galathea 8
37 (36) Rostrum subulate, with one long supraorbital spine on each
side ...... Munida
38 (3) Abdomen bent under cephalothorax; uropods lacking...... 39 0 39 (40) Fifth pair of pereods very short, concealed under carapace,
due to which organisms appear to have four pairs of legs ...Lithodes
40 (39) Fifth pair of pereopods do not differ greatly in size from
other pairs of legs ...... 41
41 (42) Rostrum long and sharp ...... Macropodia
42 (41) Rostrum short and obtuse ...... 43
43 (44) Length of carapace considerably greater than width...... Hyas
44 (43) Length of carapace approximately equal to width ..... Chionoecetes
Suborder Macrura natantia
FamilyH-op l opho ridae Faxon
Genus H y m e n o d o r a Sars
Hymenodora glacialis (Buckholz) (plate LXXXVII, 1)
Rostrum short;^lagella of antennae very long. Length 50-80 mm.
Bathypelagic species. Encountered in Polar basin, as well as in
Bering Sea and Sea of Okhotsk. Family P a n d a 1 i d a e Bate Genus P a n d a 1 u s Leach
Key to Pandalus species encountered in northern seas of the USSR
1 (2) End of rostrum lacking teeth along top for not more than
one-third of its length ...... P. borealis
2 (1) About one-half of rostrum lacking teeth ...... 3
3 (4) Third segment of abdomen smooth ...... P. annulicornis
4 (3) Third segment of abdomen with ridge ...... P. goniurus
Pandalus borealis Krôyer (plate LXXXVII, 2)
Rostrum narrow, almost straight, slightly curved upward; more than
length of carapace. Number of teeth on upper edge, including teeth of 9 dorsal ridge of carapace, which begins slightly before its middle, varies from 12 to 16; last 4-5 teeth belong to carapace. Only most terminal part of rostrum (not more than one-third of its length) lacks teeth. Lower edge of rostrum bears 7-8 teeth which diminish in size distally, 2 small denticles on its end. Posterior end of third abdominal segment bears obtuse process.
Telson carries longitudinal row of teeth (varying in number from 7 to 12) on each side; of the four apical teeth present both inner ones shorter than outer ones. Eyes large; black spot ("accessory eye") observed near inner edge of facetted part on dorsal side. Antennules bear two approximately equal flagella; proximal part of outer flagellum considerably thicker than distal part. Antennae with long flagellum exceeding length of entire body, highly brittle and so easily broken off. Supraorbital spines lacking,
spines present only at base of scaphocerites and on anterior lower corner
of carapace. First two pairs of maxillipeds lamellose, biramous. Third
pair of maxillipeds without exopodites, resemble walking legs. First pair
of pereopods with sharp ends formed by cuspidate fingers of microscopically
small chelae. Second pair of pereopods differ in length; left pereopod with
carpopodite of approximately 50 secondary segments is considerably longer (333) than right pereopod with approximately 20-24 secondary segments in carpo-
podite. Living specimens usually red; antennal flagella with alternating
red and white parts. Length up to 125-145 mm.
P. borealis belongs to group of boreo-arctic species. Frequently en-
countered in vast numbers in deeper layers of water in Barents Sea. Repro-
duces in winter. Extremely rare in White and Kara seas.
Variety P. borealis var. edenticulatus Retowsky, characterized by
absence or poor development of teeth on upper edge of rostrum, observed in
northern part of Kara Sea. 10
Pandalus annulicornis Leach (=P. montagui Leach)
(plate LXXXVII, 3)
Distinguished from preceding species by armature of rostrum, having
9-12 spinelike teeth on top and 5-6 teeth below; almost entire anterior half of upper edge of rostrum without teeth, only end bears two denticles.
Telson with 6 pairs of lateral spines. Length 70-90 mm (up to 160 mm).
Boreal species, encountered in Barents and White seas. Variety
P. annulicornis var. tridens Rathbun encountered in Bering Sea.
Pandalus g oniurus Stimpson (plate LXXXVII, 4) Boreal, Pacific
, species. Encountered in Chukchq and in Far Eastern seas.
Genus P a n d a 1 i n a Calman
Pandalina brevirostris (Rathke) (plate LXXXVII, 5) Carpopo.dite of right pereopod of second pair divided into four secondary segments. Length up to
33 mm. Boreal species. Encountered in western part of Barents sea.
Family H i p p o 1 y t i d a e Ortmann
Genus S p i r o n t o c a r i s Bate
Key to,SDirontocaris species encountered
in northern seas of the USSR
1 (2) Upper plateof rostrum located above axis considerably narrower
than lower plate ...... S. turgida
2 (1) Width of upper plate of rostrum equal to or greater than that
of lower plate ...... 3
3 (4) Axis of rostrum straight; upper plate of rostrum finely serrate..
...... S. murdochi
4 (3) End of axis of rostrum curved upward; upper plate of rostrum with
more or less large teeth ...... 5
5 (6) Teeth of carapace and upper edge of rostrum do not form regûlar
arcuate line in profile...... S. arcuata 11
6 (5) Teeth of carapace and upper edge of rostrum do not form
regular arcuate line ...... 7
7 (8) Teeth of carapace begin almost at very posterior edge of
cephalothorax ...... S. spirius
8 (7) Teeth of carapace begin approximately one-third of length of
cephalothorax away from posterior margin of latter....S: securifrons
Spirontocaris'(Hippolÿte) spi nusrius (Sowerby)
(plate LXXXVII, 6)
Rostrum knifelike, expanded in the form of a plate at the top and bottom, with median axis curved upward at end and commonly projecting in the form of a distinct peak, below which there is a fairly large semicircular notch. Ridge of carapace, which begins almost at the very posterior edge (334) of cephalothorax, bears 4-5 high teeth curved anteriorly like a sickle and frequently with fine serration along upper edge; cephalothorax highly convex in profile. Upper edge of rostrum with small teeth or fine serration; lower edge smooth or with few teeth. Nature of serration and shape of rostrum end highly variable. Anterior of carapace with four spines on each side,
of which two supraorbital ones are located behind the eye orbit, the third
at the base of the scaphocerite and the fourth on the anterior lower corner
of the carapace. Posterior edge of third segment of abdomen on dorsal side bears uncinate process overlapping adjacent segment. Length up to 50-60 mm.
Arctic, sublittoral species. Frequently encountered in Barents and
White seas.
S. spinus var. intermedius Makarov (plate LXXXVII, 7) encountered in
Chukcha, Bering and Okhotsk seas. Distinguished by lower carapace, the
teeth of which form an almost regular straight line, and by the small size
of the notch at the end of the rostrum under the axial spine. 12
Spirontocaris (Hippolyte) securifrons (Norman)
(=S. lilljeborgi Danielssen) (plate LXXXVII, 8)
Very similar to preceding species with which it was previously confused. Distinguished by following features. Teeth of carapace begin approximately one-third of length of cephalothorax away from posterior edge of latter instead of at the very edge; these teeth are sharp and usually smooth, smaller than in S. spinus, and gently curved toward the anterior.
Posterior edge of third abdominal segment without large process.
Boreal species. Encountered in western part of Barents Sea.
Spirontocaris (Hippolyte) turgida (Krgyer)
(=S. phippsi Kr.gyer) (plate LXXXVII, 9)
Rostrum straight, knifelike, slightly narrowed toward base. Lower plate considerably wider than upper one. Ridge of carapace, which begins approximately at middle of cephalothorax, bears 3-4 narrow teeth obliquely directed toward the anterior. Upper edge of rostrum with 6-9 teeth, lower edge with 4-7 teeth. Each side of carapace carries four spines arranged similarly to those in S. spinus; anterior supraorbital spine at edge of orbit small and barely visible. Telson with 5-6 pairs of spines. Males distinguished by narrow rostrum and almost complete absence of teeth on carapace. Length up to 52 mm.
S. turgida belongs to group of Arctic, circumpolar species. En- countered in coastal areas of all northern and Far Eastern seas of USSR.
Spriontocaris arcuta'Rathbun (plate LXXXVII, 10)
Spirontocaris murdochi Rathbun (plate LXXXVII, 11)
Both Pacific, boreal species encountered in Chukcha and Far Eastern seas (besides these, several other Spirontocaris species are encountered in Far Eastern seas). 13
Genus Hetairus Bate
Hetairus (Spirontocaris=Hippolyte) polaris (Sabine)
(plate LXXXVIII, 1)
Rostrum equal to carapace in length; upper edge almost straight, teeth of lower edge closer to end of rostrum. Anterior of carapace with three spines on each side, first spine behind eye orbit, second at base of scaphocerite, third on anterior lower corner of carapace. Telson with 6-8 pairs of spines. Males distinguished by absence of teeth on upper edge of rostrum. Length up to 40-70 mm.
Arctic-boreal species, widely distributed in sublittoral of all northern and Far Eastern seas of USSR (several other Hetairus species en- countered in Far Eastern seas). Reproduces in Barents Sea in July-August.
Genus Eualus Thallwitz (335) Eualus (Spirontocaris=Hippolyte) gaimardi
(Milne-Edwards) (plate LXXXVIII, 2-4) Rostrum knifelike, slightly curved upward, begins in the form of a ridge in anterior third of carapace. Front of carapace with two spines on each side, first spine at base of scaphocerite, second spine on anterior lower corner of carapace; supraorbital spines lacking.
Among the most common members of the family Hippolytidae encountered in northern seas of the USSR. Two varieties differing in a number of characteristics from type-form distinguished.
Eualus gaimardi typ. (plate LXXXVIII, 2)
Rostrum in females usually shorter, scaphocerite longer in males.
Carapace with 2-3 dorsal teeth; rostrum with 3-6, mostly 4 teeth, at the top, 2-6 teeth at the bottom. Telson usually with 5-6 pairs of lateral spines. Posterior edge of third abdominal segment lacking process in females, in rare cases with insignificant process in males. Length of 14 females up to 58 mm, length of males up to 41 mm.
Encountered in sublittoral of Barents and White seas.
Eualus gaimardi var. gibba (Krôyer) (plate LXXXVIII, 3)
Rostrum in females approximately equal in length to scaphocerites, rostrum in males longer than scaphocerites. Carapace with 2-3 dorsal teeth; rostrum with 4-6, mostly 5 teeth, at the top, 2-4 teeth at the bottom.
Telson usually with 5-7 pairs of lateral spines. Posterior edge of third abdominal segment in females without process, obtuse process present in males. Length of females up to 66 mm, length of males up to 55 mm.
Encountered along Spitsbergen coast and western shores of Novaya
Zemlya.
Eualus gaimardi var. belcheri (Bell)
(plate LXXXVIII, 4)
Rostrum in females and males usually considerably longer than scapho- cerites. Carapace with 2-4 dorsal teeth; rostrum with 4-10, mostly 6 teeth, at the top, 3-6 teeth at the bottom. Telson usually with 7-9 pairs of lateral spines. Posterior edge of third abdominal segment with well- developed process in females, with sharp uncinate process in males. Length of females up to 70 mm, length of males up to 57 mm.
Encountered in eastern part of Barents Sea and in all seas along northern coast of Siberia.
Several other Pacific species, besides E. gaimardi, are encoüntered in the Chukch& Sea I.K. suckleyi (Stimpson), E. fabricii (Kro"yer), E. camtsch- atica (Stimpson)].
Genus H e p t a c a r p u s Holmes
Heptacarpus (Spirontocaris=Hippolyte) pusiola
(Kro'yer) (plate LXXXVIII, 5)
Rostrum spinelike, shorter than eyestalks, with broad base and ridge beginning on anterior ^ of carapace. Carpopodite of second pair of 15
0 pere^pods subdivided into seven secondary segments. Supraorbital teeth lacking on carapace. Distal end of basal segment of antennular stem bears spine on top. Telson with 6 pairs of spines. Length up to 20-25 mm.
Amphiboreal species. Encountered in Barents, Chukch4 and Far Eastern Y seas.
Genus S p i r o n t o c a r e l l a Brashnikov
Spirontocarella macilenta (Krôyer) (plate LXXXVIII, 6)
Length up to 40 mm. Common form in Chukcha Sea, also encountered in
Far Eastern seas.
Genus C a r i d i o n Goës (336)
Caridion gordoni Bate (plate LXXXVIII, 7)
Mandibular palp 3-segmented. Supraorbital teeth lacking on carapace.
Length up to 27 mm.
Boreal species. Encountered in western part of Barents Sea.
Genus B y t h o c a r i s Sars
Key to Bythocaris species encountered in
northern seas of the USSR
1 (2) Median spine of rostrum longer th an lateral spines...B. simplicirostris
2 (1) Median spine of rostrum not longer than lateral spines....B. payeri
Bythocaris simplicirostris Sars (plate LXXXVIII, 8)
Median spine of rostrum longer than eyestalks. Ridge on carapace begins near middle of latter, bears two small denticles. Carpopodite of second pair
of pereopods subdivided into 12 secondary segments. Length up to 40 mm.
Encountered in western part of Barents Sea and Spitsbergen region.
Bythocaris payeri (Heller) (plate LXXXVIII, 9)
Rostrum shorter than eyestalks. Ridge of carapace poorly developed
and lacking denticles. Carpopodite of second pair of pereopods subdivided
into 9 secondary segments. Length up to 50 mm. 16
Rare, deep-sea species, encountered in Barents Sea, Spitsbergen region and in vicinity of F ranz Josef Land.
One specimen of Bythocaris irene Retowsky encountered in northern part of Kara Sea. Distinguished from other species by presence of highly un- developed, obtuse rostrum and by absence of spine on outer edge of scapho- cerites.
Family Crangonidae Bell
Genus Crangon Fabricius
Key to Crangon species encountered in
northern seas of the USSR
1 (2) Sixth segment of abdomen on dorsal side smooth . C crangon
2 (1) Sixth segment of abdomen on dorsal side with two sharp
longitudinal ridges 3
3 (4) Rostrum equal in length to scales confining eye orbits
externally C. allmanni
4 (3) Rostrum noticeably longer than scales C. dalli
Crangon crangon (Linné) (=C. vulgaris
Fabricius) (plate LXXXIX, 1)
Rostrum equal to eyestalks in length. Carapace bears three spines, one dorsal and two lateral, inserted at the same level. Length up to 55-75
MM.
Frequently encountered in freshened areas of coastal region of White
Sea, less common in Barents Sea. Boreal species.
Crangon allmanni Kinahan (plate LXXXIX, 2)
Rostrum extends only to midlength of eyestalks. Carapace bears three spines, one dorsal spine and two lateral ones slightly anterior to the first.
Length up to 100 mm.
Boreal species. Encountered in sublittoral of Barents and White seas. 17
Crangon dalli Rathbun (plate LXXXIX, 3) (337)
Length up to 50 mm. Boreal, Pacific species. Encountered in
Chukchéil and Far Eastern seas.
Genus Nectocrangon Brandt
Nectocrangon lar (Owen) (plate LXXXIX, 4)
Length up to 95 mm. One of the most common species of Chukch Sea, also encountered in Far Eastern seas. Pacific species.
Genus Sclerocrangon Sars
Key to 3..clerosx_angon. species encountered in
northern seas of the USSR
1 (2) Median ridge of carapace with two teeth S communis
2 (1) Median ridge of carapace with 3-5 teeth 3
3 (4) Epimera of second and third abdominal segments with two teeth on
lower margin on each side S. ferox
4 (3) Epimera of second and third abdominal segments with one tooth
inserted on posterior corner of lower margin on each side....S. boreas
Sclerocrangon boreas (Phipps) (plate LXXXIX, 5)
Rostrum broadly triangular, slightly longer than eyestalks, with rounded process directed downward between eyes at the bottom. Top of cara- pace bears large ridge with 3-4 large and obtuse teeth in old individuals and 4-5 sharp, anteriorly directed teeth in young forms; one smooth ridge terminating in sharp spine at front extends along each side of carapace.
Posterior corners of epimera of second and third abdominal segments terminate in short teeth. Length up to 90 mm.
Arctic, widely distributed species. Encountered in Barents, White,
Kara, Chukch4 and in Far Eastern seas.
Sclerocrangon ferox (Sars) (plate LXXXIX, 6, fig. 34)
Rostrum narrow, considerably longer than eyestalks, expanded in the shape of a knife, but without a process, at the base between the eyes. Top 18
of carapace bears ridge with three broad and sharp teeth; one ridge ending
in two spines at the front extends along each side of carapace. Epimera
of second, third and fourth abdominal segments with two teeth on lower margin, epimera of fifth segment with 3-4 sharp teeth. Length up to 130 mm.
Arctic species. Encountered in Barents and Kara seas.
Sclerocrangon communis (Rathbun) (plate LXXXIX, 7)
Length up to 50 mm. Encountered in Chukch4 and in Far Eastern seas d
(several more Pacific species of the genus Sclerocrangon are encountered in
Far Eastern seas).
Genus P o n t o p h i l u s Leach
Pontophilus norvegicus (M. Sars) (plate LXXXIX, 8)
Rostrum slightly longer than eyestalks. Top of carapace bears five
longitudinal ridges; median ridge with three large teeth, median lateral
ridges each with two teeth, external lateral ridges each with one tooth.
Length up to 75 mm.
Boreal species, encountered in western part of Barents Sea and
Spitsbergen region. Deep-sea species.
Genus S a b i n e a Owen (338)
Key to Sabinea species encountered in
northern seas of the USSR
1 (2) Rostrum obtuse ...... S. septemcarinata
2 (1) Rostrum sharp ...... S. sarsi
Sabinea septemcarinata (Sabine) (plate LXXXIX, 9)
Rostrum somewhat longer than eyestalks. Carapace with seven longi-
tudinal serrated ridges, median ridge usually bears 4-5 teeth directed
anteriorly. Telson rounded on end, with several spinules along edge.
Length up to 70-80 mm. 19
Widely distributed Arctic species. Encountered in sublittoral of all northern seas of USSR. Reproduces in Barents Sea in June-July.
Sabinea sarsi Smith (plate LXXXIX, 19)
Rostrum noticeably longer than eyestalks, with longitudinal costella tapered to a point at upper end. Carapace with seven longitudinal ridges, median ridge usually bears 7-8 teeth directed anteriorly. End of telson spinelike. Length up to 72 mm.
Boreal species. Encountered in Barents Sea and Spitsbergen region.
Suborder Macrura reptantia
Family Nephropsidae Stebbing
Genus Nephrops Leach
Nephrops norvegicus (Linné) (plate LXXXIX, 11)
Chelae of first pair of pereopods elongate, prismatic. Scaphocerites lamellose. Length of females 160-180 mm, length of males 120-140 mm.
Encountered in western part of Barents Sea.
Suborder Anomura
Family Galatheidae Dana
Genus Galathea Fabricius
Galathea strigosa (Linné) (plate XC, 1)
Rostrum triangular, with 3-4 teeth on each side. Surface of carapace with transverse grooves bearing short hairs. Chelipeds spined and hairy.
Fifth pair of pereopods small, with small chelae. Telson with deep notch.
Length up to 44 mm.
Extremely rare species, encountered in western part of Barents Sea.
Genus Munida Leach
Munida bamffica (Pennant) (=M. rugosa Sars)
(plate XC, 2)
Rostrum resembles sharp spine; shorter supraorbital spines along 7 20 0
sides. Chelipeds very long and narrow. Fifth pair of pereopods small.
Telson with notch. Length up to 48 mm.
Rare boreal species. Encountered in Barents Sea.
Family P a g u r i d a e Dana (339)
Paguridae, the hermit crabs, which live in mollusk shells, are dis-
tinguished by a soft, asymmettical abdomen, most commonly spiral-shaped. Pleo-
pods developed only on one side. Uropods have verrucous surfaces which serve
to keep the organism within the shell. Fourth and fifth pairs of pereopods
rudimentary.
Species of only one genus, Pagurus, are encountered in northern seas
of the USSR.
Genus P a g u r u s Fabricius
Key to Pag,urus species encountered in
northern seas of the USSR
1 (2) Upper surface of palma of right chela covered with long sharp
spines and long hairs ...... P. capillatus
2 (1) Upper surface of palma of right chela covered with short spines;
hairs short or lacking ...... 3
3 (4) Upper surface of palma of right chela covered with small and obtuse
granules which give it a shagreen appearance; hairs barely
noticeable ...... P. bernhardus
4 (3) Upper surface of palma of right chela covered with prickly granules;
hairs almost lacking or short, arranged in bundles ...... 5
5 (6) Entire surface of carapace hard ...... P. splendescens
6 (5) Only front part of carapace hard ...... 7
7 (8) Fingers of left chela not curved downward ...... P. pubescens
8 (7) Fingers of left chela strongly curved downward on distal
ends ...... P. rathbuni 21
Pagurus (Eupagurus) pubescens Krgyer (plate XC, 3)
Front part of carapace greater in length than width. Eyestalks almost cylindrical, with very weakly defined coarctation in middle. Top of right chela covered with prickly granules, with bundles of short hairs anterior to their bases. Length of right chela almost twice greater than its maximum width. Propodite of left chela with longitudinal ridge, carpopodite with two longitudinal rows of spines along edges of upper sur- face. Tips of all segments of walking legs red. Length up to 100 mm.
Lives in shells of Buccinum, Neptunea and other mollusks. (.4," Amphiboreal species. Encountered in Barents, White, Chuk.4 and also A Far Eastern seas; extremely rare in Kara Sea.
Pagurus (Eupagurus) bernhardus (Linné) (plate XC, 4)
Length and width of front part of carapace usually the same. Eye- stalks short, sharply defined coarctation in middle. Surface of right chela covered with tiny obtuse granules which imparts shagreen appearance; in middle of palma larger granules form two oblique lines converging at base of movable finger. Length of right chela approximately 1-1- times greater than its maximum width. Propodite of left chela lacking longitudinal ridge.
Length up to 100 mm.
Boreal species. Encountered in western half of Barents Sea.
Pagurus splendescens Owen
Pagurus rathbuni (Benedict)
Paeurus capillatus (Benedict)
All three species encountered in Chukcha Sea and in Far Eastern seas.
Family Lithodidae Bouvier
Genus Lithodes Latreille
Lithodes maja (Linné) (plate XC, 5)
Body crab-shaped, highly calcareous. Carapace broad, covered with spines. Rostrum long, bears eight spines, biramous on end. Scaphocerites 22 rudimentary. Pereopods with long spines. Right chela larger than left (340) one. Body of young individuals covered with numerous spines, traces of which remain in the form of tubercles on carapace in mature individuals.
Abdomen short and broad, bent under cephalothorax, asymmetrical in females.
Pleopods in females rudimentary, paired on first abdominal segment, present only on left side of other segments; uropods lacking. Pleopods and uropods lacking in males. Length of carapace up to 145 mm.
Largest member of Decapoda encountered in northern seas of USSR, boreal species. Encountered in sublittoral of Barents Sea and Spitsbergen region.
Suborder Brachyura
Family Majidae Alcock
Genus Hyas Leach
Key to Hyas species encountered in northern
seas of the USSR
1 (2) Cephalothorax barely expanded behind external corners of
eye orbits' . H. araneus
2 (1) Cephalothorax highly expanded behind external corners of eye
orbits, as a result of which a deep coarctation is formed in
upper third of carapace H. coarctatus
Hyas araneus (Linné) var. hoeki Birula
(plate XCI, 1)
Cephalothorax gradually expands posteriorly; outer edges behind eye orbits slightly expanded and curved somewhat. Length of rostrum, consist- ing of two closely contiguous lobes, equal to or less than its width at base (rostrum longer in type form). Length of palma of chelipeds from its base to articulation with movable finger always less than latter. Pereopods
cylindrical. Red in colour. Length of cephalothorax up to 70-100 mm. 23
H. araneus var. hoeki belongs to group of Arctic-boreal species.
Encountered in Barents and White seas, eastward to Karskiye Vorota and
Yugorskiy Shar.
Hyas coarctatus Leach (plate XCI, 2)
Cephalothorax highly expanded posteriorly; outer edges behind eye orbits resemble spherical expansions; behind these cephalothorax very narrow, a deep coarctation separating head from thoracic part. Length of palma of chelipeds frôm its base to articulation with movable finger may be
greater (usually in males) or smaller than latter.
Type form,. H. coarctatus typ. (plate XCI, 2), with carapace up to
35-40 mm in length, encountered in Barents Sea.
Variety H. coarctatus var. alutaceus Brandt (plate XCI, 3) distinguished from type form by larger body size (length of carapace up to 50-80 mm) and
shorter rostrum equal to 1/7-1/9 length of carapace (1/4-1/6 length of cara- pace in typical form). Encountered from New Siberian Islands to Chukch4)
Sea, as well as in Far Eastern seas.
Genus C h i o n o e c e t e s Kro"yer
Chionoecetes opilio (Fabricius) (plate XCI, 4)
Cephalothorax spherical. Rostrum with two lobes separated by wide
triangular notch. Perds long, flattened. Length of cephalothorax up to
126 mm, width up to 128 mm.
Encountered in Chukcha and in Far Eastern seas.
Genus M a c r o p o d i a Leach (341)
Macropodia (Stenorhynchus) rostrata (Linné)
(plate XCI, 5)
Carapace triangular, drawn out in long rostrum anteriorly. Eyes on
long stalks, protruding far out of almost parallel orbits. Front part of
cephalothorax separated from posterior part by coarctation. Top of carapace 24
.
bears two spines, one in front of coarctation, the other at posterior end
of carapace.
Rare, boreal species. Encountered in Barents Sea.
Key to larval stages of Decapoda encountered in
northern seas of the USSR1
1 (4) Carapace with one dorsal and two lateral spines ...... 2
2 (3) Telson notch deep; each lobe holds three setae and two
spines ...... Hyas (p. 344)
3.(2) Telson notch shallow; each lobe holds five setae .... Chionoecetes
4 (1) Carapace lacking dorsal and lateral spines ...... 5
5 (8) Abdomen with one or several(unpaired) long dorsal spines...... 6
6 (7) Abdomen with one long dorsal spine ...... Pontophilus
7 (6) Abdomen with several (unpaired) long dorsal spines...Nephrops
8 (5) Abdomen lacking long dorsal spines (only short dorsal spines
present in some species) ...... 9
Posterior margin of carapace with more or less deep notch...... 10
Inner edge of notch of carapace smooth ...... 11
Rostrum not less than i length of carapace ...... Pagurus (p. 343)
Rostrum less than Z length of carapace ...... Lithodes (p. 343)
Inner edge of notch of carapace with spines ...... 14
Lateral ends of notch of carapace drawn out into long spines,
reaching at least end of third abdominal segment ...... Munida
15 (14) Lateral ends of notch of carapace extend at most to end of second
abdominal segment ...... Galathea
16 (9) Posterior end of carapace straight or slightly concave...... 17
1Development of Bythocaris simplicirostris Sars and Sclerocrangon boreas (Phipps), which have large eggs, takes place without metamorphosis. 25
17 (18) All segments of abdomen with one or two pairs of lateral
spines ...... Sabinea (p. 343)
18 (17) Lateral spines lacking or present only on last abdominal
segment ...... 19
19 (22) Supraorbital spines lacking at all stages ...... 20
20 (21) Last abdominal segment with short lateral spines....Crangon (p. 342)
21 (20) Abdomen without spines ...... Sclerocrangon (p. 343)
22 (19) Supraorbital spines present (lacking in first stage only in
certain species) ...... 23
23 (24) Endopodites of front pairs of legs with expanded terminal
segments ...... Caridion
24 (23) Terminal segments of endopodites of legs not expanded...... 25
25 (26) Fifth abdominal segment without dorso^-lateral spines ......
...... Pandalus (p. 342)
26 (25) Fifth abdominal segment with dorso-lateral spines (lacking in
Heptacarpus) ...... Spirontocaris s.l. (p.342)
Description of larval stages of some species (342)
of Decapoda encountered in northern sèas of the USSR
Larval stages of Pandalus borealis Kro"yer
(plate LXXXVII, 2 lar. 1, 3, 7)
Apparently, seven larval and several postlarval stages in all. lst
stage: rostrum without teeth; eyes immovable; supraorbital spines lacking;
antennules 2-segmented, antennae with 1-segmented endopodites; endopodites
of second pair of maxillipeds unsegmented, those of third pair 5-segmented;
all pereopods rudimentary, curved at base, first three pairs biramous, last
two pairs uniramous; telson expanded on end, bilobed, not separated from
last abdominal segment. Length approximately 5 mm. 2nd stage: eyes movable,
supraorbital spines present; antennules with 3-segmented stem and rudimentary 26 flagella; antennae with 2-segmented endopodites; first three pairs of pereo- pods long, long, with multiarticulate endopodites, last two pairs short, without exopodites; pleopods rudimentary. Length approximately 8 mm. 3rd stage: rostrum with two small teeth at base; all pereopods well developed, with rudimentary gills at base; uropods with short endopodites; telson sep- arated from last abdominal segment. Length approximately 10 mm. 4th stage: rostrum with four teeth at base; pleopods biramous, with unsegmented rami; uropods with almost equal rami; telson with almost parallel lateral edges, with three pairs of lateral and five pairs of apical spines. Length approx- imately 12 mm. 5th stage: rostrum with 11-12 teeth (4-5 on carapace); flagellum of antennae multiarticulate; all pereopods of equal length; second pair of pereopods with rudimentary chelae; pleopods with setae. Length approximately 14 mm. 6th stage: rostrum with 14 teeth; last three pairs of pereopods considerably longer than front ones; second pair of pereopods with well-developed chelae; telson with almost straight posterior margin. Length approximately 15 mm. 7th stage (or 1st postlarval stage): top of rostrum with 15 teeth, bottom with 5 teeth; supraorbital spines lacking; left pereo- pod of second pair longer than right one; exopodites of first three pairs of pereopods reduced; telson with two pairs apical spines. Length approxim- ately 17 mm.
Larval stages of Pandalus annulicornis Leach
(plate LXXXVII, 3 lar. 3, 7)
Similar to developmental stages of preceding species. Distinguished by smaller size, as well as shorter rostrum and longer exopodites on pereo- pods. Length of 1st stage about 5 mm, 2nd stage 5-6 mm, 3rd stage 7-8 mm,
4th stage 9 mm, 5th stage 10 mm, 6th stage 12-13 mm.
Larval stages of Spirontocaris s. 1.
The larval stages of Spirontocaris species, as well as those of re- lated genera Eualus, Hetairus and Hepatacarpus as encountered in northern 27 seas of the USSR are almost completely unknown; descriptions have been carried out for only certain developmental stages which cannot always be applied to a given species with full certainty.
The general characteristics are as follows: rostrum short, not longer or only slightly longer than eyes; carapace with small supraorbital spines; fifth abdominal segment with dorso-lateral spines (lacking in larvae of Heptacarpus pusiola); anal spine present; telson usually expanded dis- tally, with seven pairs of different-length spines on end (spines of equal length in larvae of Hetairus polaris); endopodite of antennae spinelike
(endopodite with additional spine stemming from outer edge in larvae of
Spirontocaris securifrons, additional spine lacking in larvae of Eualus gaimardi); exopodites present on two, three (in larvae of Spirontocaris turgida) or four pairs of pereopods. First stage does not exceed 3-4 mm.
Up to nine larval stages in certain species, development shorter in northern species.
Larval stages of Crangon crangon (Linné)
(plate LXXXIX, 1 lar.)
Five larval (mysid) stages and one postlarval stage in all. Larval stages characterized by presence of small but sturdy dorsal spine directed (343) posteriorly on posterior end of third abdominal segment; fifth abdominal seg- ment elongated into cuspidate teeth along sides; rostrum sharp and thin; lateral edges of carapace with 1-3 denticles in front; long exopodites of maxillipeds and first pair of pereopods used for swimming. 1st stage: pereopods lacking. 3rd stage: first pair of pereopods with exopodites,
remaining pairs rudimentary; uropods present. 4th stage: pleopods rudimentary.
5th stage: pleopods biramous.. Postlarval stages distinguished by absence of
exopodites on pereopods and spines on abdomen. Length (Norwegian Sea): 1st
stage 1.8-2.2 mm, 2nd stage 2.8 mffi, 3rd stage 3.4 mm, 4th stage 3.8 mm, 5th
stage 4.5-4.7 mm. 28
Larval stages of Crangon allmanni Kinahan
(plate LXXXIX, 2 lar.)
Distinguished from corresponding larval stages of preceding species by absence of dorsal spine on third abdominal segment and by small size of lateral spines on fifth abdominal segment.
Larval stages of Sclerocran•on ferox (Sars)
(plate LXXXIX, 6 lar.)
Larvae emerging from eggs have highly inflated and smooth cephalo- thorax and perfectly smooth abdomen, all pairs of pereopods and pleopods present. Dactyolpodites of last two pairs of pereopods highly developed and used for attachment to maternal organism. Length (Norwegian Sea) 11 mm.
Larva with spines on abdominal segments forms after moult.
Larval stages of Sabinea septemcarinata (Sabine)
(plate LXXXIX, 9 lar.)
Two larval stages. Characterized by presence of sharp lateral spines on abdominal segments; two pairs of spines on second abdominal segment; spines of last abdominal segment directed posteriorly. 1st stage: maxilli- peds with long exopodites; all pairs of pereopods and pleopods rudimentary.
2nd stage: first pair of pereopods with exopodites; uropods present. Size
(Barents Sea) of 1st stage 11.0-11.7 mm, 2nd stage 13.0-14.5 mm.
Larval stages of Pagurus bernhardus (Linné)
(plate XC, 4 d, e)
Apparently, only two larval stages and one postlarval stage. Larval stages characterized by presence of notch on posterior end of carapace and long rostrum exceeding length of carapace. 1st stage: two pairs of maxillipeds, uropods lacking. 2nd stage: three pairs of maxillipeds, uropods present. Postlarval stage (stage of glaucothoe) distinguished by presence of asymmetrical chelipeds and uropods, leads planktonic mode of life at night. Length (Norwegian Sea) of 1st stage 3.5 mm, 2nd stage 8 mm, 29
postlarval stage 4 mm.
Larval stages of Pagurus pubèscèns Krôyer
(plate XC, 3 c)
Larval stages similar to corresponding stages of preceding species.
Distinguished by shorter rostrum, as well as by presence of long lateral
spines on fifth abdominal segment; posterior edges of carapace elongated
into long spines.
Larval stages of Lithodes maja (Linné)
(plate XC, 5 b)
lst larval stage: carapace with large lateral lobes directed toward
posterior and exterior; rostrum short, not exceeding 2 length of carapace;
abdominal segments with spines on posterior margin; two pairs of maxillipeds
used for swimming, Last larval,'stage: three pairs of maxillipeds used for swimming, rudimentary pleopods. Length (Norwegian Sea) of lst stage 6 mm, last stage 8 mm. Larval stages of Hyas coarctatus Leach (plate XCI, 1 c) (344)
Two larval.stages (zoëa) and one postlarval stage (megalopa). lst
zoëa: rostrum, dorsal and both lateral spines covered with spicules. An-
tennae with rudimentary endopodite and long process covered with spicules
equal in length to rostrum; exopodite of antennae less than Z length of
prickly process. First two pairs of maxillipeds used for swimming, remain-
ing appendages rudimentary. 2nd zoëa: endopodite of antennae developed.
Megalopa: crab-shaped body, compressed dorsoventrally, with straight ab-
domen. Rostrum consists of three spines, median one twice longer than lateral
ones. Dorsal spine of carapace long, reaches third abdominal segment. All
limbs developed, pleopods used for swimming. Length (Atlantic) of lst zoëa
1.8 mm, 2nd zoëa 3.5 mm, megalopa 3.4 mm.
Larval stages of Hyas araneus (Linné)
(plate XCI, 1 c) 30
Stage of zoëa similar to corresponding stages of preceding species.
Megalopa distinguished by shorter dorsal spine of carapace and by less dis-
tinct differences in length of rostrum spines.
CLASS PANTOPODA - PYCNOGONIDS
By Z.S. Bronshtein
A highly distinctive class of purely marine Arthropoda which stand
out among the other arthropods.
The body of pantopods consists of a trunk bearing a proboscis and
appendages, and abdomen.
The trunk is either distinctly segmented, in which caseit is clearly
seen that it is separated into four segments, or else the demarcation between
the segments is completely or partially obliterate. The anterior ocular seg- ment of the trunk, unlike all the others, is formed as a result of the fusion
of several segments. The dorsal side of this segment carries an ocular
tubercle which usually bears four small eyes. The constriction which separ-
ates the anterior segment from the second one is called the neck.
The massive cylindrical proboscis which extends anteriorly from the
trunk terminates in a mouth. The abdomen is unsegmented, poorly developed,
rod-shaped or slightly expanded distally, in the region of the anus.
The class is characterized by extremely long and powerful appendages
(as compared with the trunk) and by the fact that the digestive and reproduc-
tive systems extend from the trunk into the appendages.
The body of pantopods has a maximum of 8 pairs of appendages; there
are no appendages on the abdomen.
lst pair - chelicerae, consist of three or two segments and usually
bear chelae;they may be rudimentary or absent altogether (fig. 35, 1, 2).
2nd pair - palps. Number of segments varies; maximum number 10. Like
the chelicerae, they may be rudimentary or absent altogether.
31
3rd pair - ovigerous legs (ovigers). Frequently supplied with flat
spines arranged in 1-2 or several rows or randomly on 7-10 segments of these
legs. The male carries the egg masses emitted by the female in the ovigerous
legs. The eggs remain on these legs until the larvae hatch out.
4th -7th pairs (8th pair an exception). Attached to special extensions
of the trunk and consist of 8 segments.
The legs often bear various types of spines and hairs. The spines on
the lower side of the segments (primarily applicable to the eighth segment only,
on the sole and closer to the base of the segments are called basal spines;
those on the middle part of the sole are median spines, and those on the end
of it terminal spines. The eighth segment sometimes has a special process
known as a heel.
There is a tarsal claw consisting of a main claw and accessory claws
on the end of the eighth segment.
The length of the animal is measured from the anterior end of the (345)
proboscis to the posterior end of the abdomen; the width is measured between
the ends of the longest pair of legs when extended.
p‘trd 1 (w. A377 170717 gll oy
4tor PM* —0, %, 'e',1444iii4eseietwite ,eeeee \tg,
. .„- -- • - - _ ..• • Fig. 35. 1 -'ColosSérideià . prOboSCidea; 2 Boreonymphon roblistum; pr - proboscis, ch - chelicerae, p - palps, ov - oviger, ab - abdomen , ■4 32
Pantopoda are benthic arthropods. Many of them live only at more
or less considerable depths (up to 2000 m and more), but some are exclusively
littoral species.
Pantopods feed on the polyps of hydroids and anemones which they
wrench off with the chelicerae and suck up with the proboscis.
Key to families of the class Pantopoda
encountered in northern seas of the USSR
1 (8) Chelicerae (1st pair of appendages) present 2
2 (5) Palps (2nd pair of appendages) consist of not less than 5
segments 3
3 (4) Chelicerae and their chelae well developed; palps 5- or 7-
segmented; third pair of appendages 10-segmented in both
sexes Nymphonidae
4 (3) Chelicerae poorly developed with underdeveloped chelae or chelae
absent altogether; palps in 6-10 segments, third pair of
appendages present in both sexes Ammotheidae
5 (2) Palps consist of less than 5 segments or absent altogether 6
6 (7) Third pair of appendages in both sexes 10-segmented. Cheli-
cerae well developed, 2- or 3-segmented; palps in 1-4
segments or absent altogether Pallenidae
7 (6) Third pair of appendages present only in males, in 5-9 segments.
Chelae on chelicerae well developed; palps lacking Phoxichilidiidae
8 (1) Chelicerae lacking 9
9 (10) Palps lacking. Third pair of appendages present only in males,
9-segmented Pycnogonidae
10 (9) Palps present, well developed, 10-segmented, longer than proboscis.
Chelicerae absent altogether or in the form of rudimentary
tubercles. Third pair of appendages present in both sexes,
10-segmented Collossendeidae 33
FamilyNymphonidae Wilson (346)
Key to genera of the family Nymphonidae
encountered in northern seas of the USSR
1 (4) Ocular tubercle usually well defined. Eyes developed 2
2 (3) Body elongate, slender, smooth, legs long, slightly
pubescent Nymphon
3 (2) Body broad, pupescent on top; legs highly pubescent...Chaetonymphon
4 (1) Ocular tubercle rudimentary. Eyes lacking Boreonymphon
Genus Boreonymphon G.O. Sars
Boreonymphon robustum Bell (fig. 35, 2)
(only species)
Body thick, sturdy, expanded medially, segments distinct. Neck short, narrow. Ocular rubercle very small, paddle-shaped. No trace of eyes.
Fingers of chela highly curved, forming an almost regular circle. Length
22 mm, width 154 mm. Encountered at depths of 120-150 m and greater. Primar- ily Arctic, almost circumpolar form. Most common in Kola Gulf, encountered
in vast numbers at depths of 32-170 m. Not observed in White Sea.
Genus Nymphon Fabr.
Key to groups and species of Nymphon encountered
in northern seas of the USSR
Pycnogonids belonging to the genus Nymphon can be divided into the
following four groups depending on the form and location of the spines on
the sole of the eighth segment of the legs:
1 (2) Only small hairlike spines cover entire surface of sole of8th
segment 3rd group
2 (1) Besides small spines, sole of 8th segment also bears large
spines 3 .+i 34
. 3 (4) Basal part of sole of 8th segment of legs (propodus) bears large
spines; similar spines present on median part of sole of 8th
segment. Distal part of 8th segment (farthest from body with
small spines only ...... lst group
4 (3) Large spines only on median or distal part of sole of 8th
segment of legs ...... 5
5 (6) Only median part of sole of 8th segment of legs bears large spines,
spines small on distal and basal part ...... 2nd group
6 (5) Large spines on distal part of sole of 8th segment, sometimes also
present on median part; only small spines present on basal
part ...... 4th group
Species of lst group
1 (10) Main claw of legs equal to approximately 2 of eighth segment in
length ...... 2
2 (3) Seventh segment of legs short, proboscis very short, ocular
tubercle obtusely conical. In palps second segment equal to or less
than 3rd segment (2 -^ol,.3); 4th segment considerably smaller than 5th
one (4<45). Length 2.5-3 mm, width 15-17 mm...... N. brevirostre Hodge
(plate XCII, lb, c, e). Boreal form. Listed for Murman Coast
and Kanin Nos.
3 (2) Seventh segment fairly long, slightly shorter than eighth one;
proboscis of average length ...... 4
4 (5) Ocular tubercle flatly spherical. Neck short. Palps: 2? 3; 41i 5.
LenP•th 3 mm, width 20 mm ...... N. brevitarse
Kriiyer (plate XCII, 2 a, b, f). Arctic, almost circumpolar form.
Encountered at depths of 12-1504 m.
5 (4) Ocular tubercle conical, sharply conical or with elongate sharp (347)
apex ...... 6 46 .35 it 6 (7) Ocular tubercle sharply conical, neck long. Palps: 2= 3; 44<5.
Length up to 4.5 mm, width up to 22 m ...... N. rubrum
Hodge (plate XCII, 3 a, b, d, f). Boreal form, but distributed in
northern regions. Encountered at depths 6-164 m. Listed for White
Sea (amidst Rhodophyceae and Phaeophyceae in vicinity of Solovets-
kiye Islands).
7 (6) Ocular tubercle conical or with elongate sharp apex ...... 8
8 (9) Ocular tubercle conical; neck of average length. Palps: 24.3; 44<5.
Length up to 6 mm, width 54 mm ...... N. grossipes (Fabr.)
(plate XCII. 4) Arctic, circumpolar form. Encountered at depths
of 4-1466 m. Listed for White Sea.
9 (8) Ocular tubercle with elongate sharp apex; neck elongate. Palps:
2<3; 4^ 5...... N. mixtum Kr^yer (plate XCI, 5 b, c e).
Arctic-boreal form. Common in Kola Gulf, also listed for White Sea.
10 (1) Main claw of legs long ( slightly shorter than'8th segment), access-
ory claws small, 7th segment longer than 8th one. Flat spines of
ovigers with basal teeth and numerous tiny denticles. Neck of
average length. Ocular tubercle sharply conical. Palps: 2< 3;
4< 5. Length 7-8 mm, width 66 mm ...... N. sluiteri
Hoek (plate XCIII, lb, c, d) Arctic form. Encountered at depths
of 40-1444 m. Listed for Kola Gulf.
Species of 2nd group
1(2) Seventh segment of legs almost twice longer than 8th segment. Neck
long. Ocular tubercle on apex, obtusely spherical. Palps: 2-3;
45. Length 6 mm, width 64 mm ...... N. longitarse
Kr^yer (plate XCIII, 2b, c, e) Arctic, circumpolar form. Listed
for Kola Gulf and White Sea. 36
2 (1) Seventh segment slightly longer than eighth one, ocular tubercle
obtusely conical. Flat spines of ovigers with small number (6-7)
of medium-sized teeth. Palps: 2e 3; 445. Length 5 mm, width
45 mm N microrhynchum
G. O. Sars Arctic form. Listed for Kara and White seas.
Species of 3rd group
1 (2) Main claw on legs less than and more than 1/3 length of eighth
segment. Legs 3i times longer than body; seventh segment shorter
than 8th one. Flat spines of ovigers with two pairs of basal spines
and small number of large teeth. Ocular tubarde low with rounded
apex. Palps: 243; 4<'5. Length 3 mm, width 22 m....N. micronix
G. O. Sars (plate XCIII, 3d). Arctic form. Listed for White Sea.
2 (1) Main claw on legs approximately -A- length of 8th segment and even
considerably longer. Legs 5 times longer than body; 7:18.
3 (4) Flat spines on ovigers vary in form on one segment: either without
basal teeth with 8-9 fairly large denticles, or with two pairs of
basal teeth and broad, barely marked denticles. Ocular tubercle
fairly high, commonly with two lateral extensions. Main claw of
legs more than length of eighth segment, accessory claws small.
Palps: 2=3; 44 5. Length 6.5 mm, width 62 mm... .N. leptocheles
G. O. Sars (plate XCIII, 4b, c, d, e). Arctic-boreal form, en-
countered at depths of 9-1264 m. Barents Sea.
4 (3) Flat spines on ovigers of same form 5
5 (6) Flat spines on ovigers without basal teeth, with very small dent-
ides. Ocular tubarde low, with flatly truncated or rounded apex.
Main claw barely reaches or does not reach halfway point of segment; (348) accessory claws small. Palps:. 2>-3; Length 15 mm, width 37
150 mm N stroemii Krgyer (plate XCIII, 5b, c, d, e, f)
Arctic-boreal form. Encountered at depths of 20-534 m. Quite common
in Kola Gulf. Encountered on various bottoms, but prefers muddy ones.
6 (5) Flat spines on ovigers large and serrated, with numerous large
denticles lacking basal teeth. Ocular tubercle high, with flatly
truncated apex. Accessory claws of legs equal to 2/3 of ocular
claw. Chelicerae slender, long. Chelae very long; both fingers end
in curved tip. Length 8 mm, width 85 mm N macrum Wilson
(plate XCIII, 6b, c, d, e, f). Arctic-boreal form. Encountered
at depths of 9-1264 m. Barents Sea.
Species of 4th group
Main claw of legs equal to â length of eighth segment, accessory
claws to â of main claw; 7:1- 8; legs 5 times longer than body. Flat spines
of ovigers with tiny denticles. Three sharply conical tubercles at midline
of dorsum. Ocular tubercle with obtusely rounded apex. Palps: 2:73,
475. Length 12 mm, width 117 m N serratum G.O. Sars (plate XCIV,
lb, c, e, f). Arctic form. Encountered at depths of 49-490 m. Listed
for Kola Gulf.
Genus Chaetonymphon G.O. Sars
Key to Chaetonvmphon species encountered in
northern seas of the USSR
1 (2) Body oval, ocular tubercle without lateral tubercles; main claws
of legs lâ times shorter than eighth segment or less than â its
length. Basal part of chelicerae elongate-oval; 8th segment of
legs expanded in basal part. Length 6 mm, width 33 mm....Ch. hirtum
Kr6yer Arctic-boreal form. Encountered at depths of 22-1844 m.
Listed for White Sea. 2 (1) Body form, ocular tubercle and main claw of legs as in preceding
species. Basal part of 2nd segment of chelicerae expanded dis-
tally. Eighth segment of legs uniformly narrowed distally.
Length 8-11 mm, width 50-70 mm Ch. spinosum Goodsir. Arctic,
almost circumpolar form. Depths up to 1500 m. Very common in
Kola Gulf where it is encountered in vast numbers.
Family Pallenidae Wilson
Key to genera of the family Pallenidae
encountered in northern seas of the USSR
1 (2) Proboscis conical with mamillary appendage at apex and corolla of
setae around mouth. Chelae 2-segmented, chelicerae short, thick,
lacking teeth along inner edges. Palps lacking. In males 5th
segment on ovigers with paddle-shaped process on distal end; 4
terminal segments also bear serrated smooth-edged spines arranged
in one row. Claws serrated. Fourth segment of legs in females
highly inflated, same segment in males with numerous openings of
adhesive glands. 8th segment with individual basal spines,
accessory claws lacking Pseudopallene
2 (1) Proboscis cylindrical with mamillary appendage, without corolla
of setae around mouth. Chelae of 2-segmented chelicerae very
short and thick; lamellar extension, serrated or smooth, on inner
margin of immovable finger of chelae. Palps lacking. Ovigerous
leg 10-segmented; its 5th segment with paddle-shaped process on
distal end. Four terminal segments each carry one row of lamellar
cuspidate spines; terminal serrated claws present 4th segment
of legs in females only slightly inflated or slightly wider than
in males Cordilochelle r Genus P seudop allene Wilson
Pseûdôpâ.lléne circulâ.ris Goodsir
Body almost clypeate, distinctly segmented, 2nd and 3rd segments
carry spinelike processes in middle of dorsal surface. Proboscis shorter
than ocular segment, cylindrically conical. Mouth surrounded by corolla of
setae. Ocular tubercle low, obtusely spherical. Chela short, Inner margin
of movable finger smooth. Ovigerous legs not longer than body. Legs
slightly more than twice longer than body, yellowish brown. Length 3.5 mm,
width 19 mm.
Arctic form; depths of 10-400 m. Listed for Kola Gulf and White Sea.
Pseudopallene spinipes Fabr.
Distinguished from P. circularis by less expanded body, with smooth
dorsal surface, without spinelike processes, by longer legs (4 times longer
than body), and by a number of other less significant characteristics.
Length 4.5 mm, width 39 mm.
Arctic form; depths of 6-380 m. Listed for White Sea and Kola Gulf.
Genus C o r d i 1 o c h e 1 1 e G.O. Sars
Cordilochelle brevicollis G.O. Sars
Body oval, ocular segment shorter than remaining part of trunk. Pro-
boscis cylindrical, rounded on end, almost as long as ocular segment. Ocular
tubercle very low, rounded, eyes developed. Immovable finger of chelae with
lamellar unserrated expansion, inner margin of movable finger smooth. Pa1ps
lacking. Lanceolate, broad, cuspidate, flat spines of oviger lacking teeth,
only with undulate edges. Legs almost four times longer than body. Length
10 mm, width 80 mm..
Arctic form. Encounteréd at depths of 12-650 m. Listed for Kola Gulf. `.r 40
Family Phoxi chili diidae Sars
Key to gerierà of the family Phoxichilîdiidae
ei^côuntered in northérn seas of the USSR
1 (2) Ocular tubercle located slightly anterior to middle. Chelicerae
strong and contracted ...... Phoxichilidium
2 (1) Ocular tubercle located on anterior end of cephalic segment. Cheli-
cerae weak and slender ...... Anoplodactylus
Genus Phôxi chilidium Rathke
Phoxichilidium femoratum (Rathke) (plate XCIV, 2a, g)
Body smooth, fairly strong and thick. Ocular segment shorter than
following two segments. Proboscis does not exceed 2 length of remaining part
of trunk, cylindrical. Ocular tubercle low, obtusely conical. Chelicerae
longer than proboscis, smooth, first segment cylindrical, overlaps end of
proboscis and slightly curved inward. Oviger in male not longer than body
(without porboscis); all its segments curved; three uncinate spines on fifth
segment. Legs 22 times longer than body, slightly pubescent; main claw more
than 2 length of 8th segment; accessory claws small. Length up to 4 mm,
width 26 mm. From reddish to brown in colour.
Arctic-boreal form, encountered at depths up to 200 m. Listed for
Kola Gulf and White Sea.
Genus A n o p lo dactylus Wilson (350)
Anoplodactylus petiolatus (Kr^yer)
Ocular segment equal to following three segments in length. Ocular
tubercle very high, cylindrical, with conical apex and slightly protruding
corners. Chelicerae longer than proboscis. Ovigerous legs equal to length
of body without proboscis. Legs slightly more than twice longer than body;
main claw slightly shorter than 8th segment, accessory claws rudimentary,
barely visible. Length 2 mm, width 10 mm. Males smaller than females. 41
Boreal species, listed for Kola Gulf.
Family Ammotheidae Dohrn
Key to genera of the family Ammotheidae
encountered in northern seas of the USSR
1 (2) Proboscis consists of two distinctly separate parts: cylindrical
main part and spindle-shaped or ovate terminal part bent under abdomen
with mouth directly posteriorly Eurycyde
2 (1) Proboscis not divided into two parts, narrowed at base, obliquely
directed downward Ammothea
Genus Eurycyde Schinte
Eurycyde hispida Kreiyer (plate XCIV, 3)
Only species belonging to this genus. First pair of appendages
3-segemented. Chelae of mature forms resemble rudimentary appendage with process on it. Main claw of legs lacking accessory claws. Ocular tubercle high and located in middle of dorsal side of ocular segment. Length without proboscis 2.5 mm, width 10 mm.
Arctic form. Encountered at depths of 100-400 m. Listed for Kola
Gulf.
Genus Ammothea Hodge
Ammothea borealis Schomk (plate XCIV, 4)
Eighth segment of legs without individual basal spines on sole. Oviger- ous legs without serrated spines. Proboscis oval, almost equal in length to
trunk, flatly truncated in front. Chelicerae 2-segmented with two small tubercles
on top of 2nd segment; chelae sometimes also preserved in mature males. Main
claw of legs not longer than 1/3 of 8th segment, accessory claws equal to 2/3
of main claw. Length 5 mm, width 25 mm.
Arctic form. Encountered at depths of 16-40 m. Listed for White Sea. 42
Ammothea echinulata Hodge (plate XCIV, 5)
Eighth segment of legs with individual basal spines on sole. Ovigerous legs carry serrated spines. Legs densely covered with hairs and spines. 2nd segment of legs in males has VATO pairs of conical tubercles with one spine each. Palps: 27.4. Yellowish in colour. Length 2 mm, width 7 mm.
Boreal form. Listed for White Sea.
Ammothea laevis Hodge (plate XCIV, 6)
Eighth segment as in A. echinulata. Oviger also with serrated spines.
2nd segment of legs without tubercles. Palps: 27-4. Length 1.5 mm, width
6 mm.
Boreal form. Encountered at depths of 35-55 m. Listed for White Sea.
Family Pycnogonidae Wilson (351)
Genus Pycnogonum Brünnich
Pycnogonum littorale Strgm
Five conical tubercles on dorsal side of body. Proboscis almost equal to length of body and directed more or less horizontally; beginning cylindric- al, end conical. Chelicerae and palps absent. Ovigerous legs present only in males, short, barely reach last segment of body. Legs shorter than body, thick and strong; main claw equal to length of 8th segment, no trace of accessory claws. Females: length 15 mm, width 26 mm. Males smaller.
Most likely of boreal origin, but thrives quite well in colder waters.
Quite common in Kola Gulf at depths up to 380 m. Encountered in warmer seas and in littoral, as name indicates.
Family Colossendeidae Hoek
Genus Colossendeis Jarzynsky
Colossendeis proboscidea Sabine (fig. 35, 1)
Body quite large compared with other pantopods: up to 50 mm long
(without proboscis) and 225 mm wide. Proboscis of enormous size, more than twice longer than trunk (without abdomen); anterior part highly expanded
(twice thicker than trunk) and slightly curved and directed obliquely down- ward. Proboscis conical at base. Ocular tubercle sharply conical, lacking distinct eyes. Chelicerae absent altogether. Palps 10-segmented, longer than proboscis. Ovigerous legs twice longer than proboscis. Length of legs in females more than twice longer than body. Main claw equal to 2/3 of eighth segment. Bright red or reddish yellow in colour.
Arctic form. Encountered at depths of 35-2206 m. Listed for Kola
Gulf.